Conventionally, a clean bench is often used as an apparatus for improving air cleanliness of a local work space. In a typical clean bench, only a front side of the work bench has an opening for performing work and sides thereof other than the front side form an enclosure in order to maintain cleanliness. In such a clean bench, a clean air outlet is arranged in the enclosure, and a worker puts his or her hands therein from the front opening for working to perform work.
However, the opening for working in the clean bench is narrow. Accordingly, for workers performing the assembly of precision instrument or the like, there is a problem with workability. In addition, as in a production line, when work involves the transfer of manufactured articles or manufacturing components, procedures such as arrangement of the entire line in the clean room have been taken. This is, however, problematic in terms of increasing the size of equipment.
Therefore, a local air cleaning apparatus has been proposed in which air flow opening faces of a pair of push hoods capable of blowing out a uniform flow of cleaned air are arranged opposite to each other to cause collision of air flows from the respective air flow opening faces so as to allow a region between a pair of push hoods to be a clean air space having higher cleanliness than other regions (Patent Literature 1).